This invention generally relates to novel compounds, pharmaceutical compositions and their use. This invention more specifically relates to novel heterocyclic compounds that bind to chemokine receptors, including CXCR4 and CCR5, and demonstrate protective effects against infection of target cells by a human immunodeficiency virus (HIV).
Approximately 40 human chemokines have been described, that function, at least in part, by modulating a complex and overlapping set of biological activities important for the movement of lymphoid cells and extravasation and tissue infiltration of leukocytes in response to inciting agents (See, for example: P. Ponath, Exp. Opin. Invest. Drugs, 7:1-18, 1998; Baggiolini, M. Nature 392, 565-568 (1998); Locati et al. Annu. Rev. Med. 50, 425- 40 (1999)). These chemotactic cytokines, or chemokines, constitute a family of proteins, approximately 8-10 kDa in size. Chemokines appear to share a common structural motif, that consists of 4 conserved cysteines involved in maintaining tertiary structure. There are two major subfamilies of chemokines: the xe2x80x9cCCxe2x80x9d or xcex2-chemokines and the xe2x80x9cCXCxe2x80x9d or xcex1-chemokines. The receptors of these chemokines are classified based upon the chemokine that constitutes the receptor""s natural ligand. Receptors of the xcex2-chemokines are designated xe2x80x9cCCRxe2x80x9d while those of the xcex1-chemokines are designated xe2x80x9cCXCRxe2x80x9d.
Chemokines are considered to be principal mediators in the initiation and maintenance of inflammation (see Chemokines in Disease published by Humana Press (1999), Edited by C. Herbert; Murdoch et al. Blood 95, 3032-3043 (2000)). More specifically, chemokines have been found to play an important role in the regulation of endothelial cell function, including proliferation, migration and differentiation during angiogenesis and re-endothelialization after injury (Gupta et al., J. Biol. Chem., 7:4282-4287 (1998); Volin et al Biochem. Biophys Res. Commun. 242, 46-53 (1998)). Two specific chemokines have been implicated in the etiology of infection by human innunodeficiency virus (HIV).
In most instances, HIV initially binds via its gp120 envelope protein to the CD4 receptor of the target cell. A conformational change appears to take place in gp120 which results in its subsequent binding to a chemokine receptor, such as CCR5 (Wyatt et al., Science, 280:1884-1888 (1998); Rizzuto et al. Science, 280:1949-1953 (1998); Berger et al. Annu. Rev. Immunol. 17: 657-700 (1999)). HIV-1 isolates arising subsequently in the infection bind to the CXCR4 chemokine receptor.
Following the initial binding by HIV to CD4, virus-cell fusion results, which is mediated by members of the chemokine receptor family, with different members serving as fusion cofactors for macrophage-tropic (M-tropic) and T cell line-tropic (T-tropic) isolates of HIV-1 (Carroll et al., Science, 276: 273-276 1997; Feng et al. Science 272, 872-877 (1996); Bleul et al. Nature 382, 829-833 (1996); Oberlin et al. Nature 382, 833-835 (1996); Cocchi et al. Science 270, 1811-1815 (1995); Dragic et al. Nature 381, 667-673 (1996); Deng et al. Nature 381, 661-666 (1996); Alkhatib et al. Science 272, 1955-1958, 1996). During the course of infection within a patient, it appears that a majority of HIV particles shift from the M-tropic to the more pathogenic T-tropic viral phenotype (Blaak et al. Proc. Natl. Acad. Sci. 97, 1269-1274 (2000); Miedema et al., Immune. Rev., 140:35 (1994); Simmonds et al. J. Virol. 70, 8355-8360 (1996); Tersmette et al. J. Virol. 62, 2026-2032, 1988); Connor, R. I., Ho, D. D. J. Virol. 68, 4400-4408 (1994); Schuitemaker et al. J. Virol. 66, 1354-1360 (1992)). The M-tropic viral phenotype correlates with the virus""s ability to enter the cell following binding of the CCR5 receptor, while the T-tropic viral phenotype correlates with viral entry into the cell following binding and membrane fusion with the CXCR4 receptor. Clinical observations suggest that patients who possess genetic mutations in CCR5 appear resistant, or less susceptible to HIV infection (Liu et al. Cell 86, 367-377 (1996); Samson et al. Nature 382, 722-725 (1996); Michael et al. Nature Med. 3, 338-340 (1997); Michael et al. J. Virol. 72, 6040-6047 (1998); Obrien et al. Lancet 349, 1219 (1997); Zhang et al. AIDS Res. Hum. Retroviruses 13, 1357-1366 (1997); Rana et al. J. Virol. 71, 3219-3227 (1997); Theodorou et al. Lancet 349, 1219-1220 (1997). Despite the number of chemokine receptors which have been reported to HIV mediate entry into cells, CCR5 and CXCR4 appear to be the only physiologically relevant coreceptors used by a wide variety of primary clinical HIV-1 strains (Zhang et al. J. Virol. 72, 9307-9312 (1998); Zhang et al. J. Virol. 73, 3443-3448 (1999); Simmonds et al. J. Virol. 72, 8453-8457 (1988)). Fusion and entry of T-tropic viruses that use CXCR4 are inhibited by the natural CXC-chemokine stromal cell-derived factor-1, whereas fusion and entry of M-tropic viruses that use CCR5 are inhibited by the natural CC-chemokines namely, Regulated on Activation Normal T-cell Expressed and Secreted (RANTES) and Macrophage Inflammatory proteins (MIP-1 alpha and beta).
In addition to serving as a co-factor for HIV entry, the direct interaction of virus-associated gp120 with CXCR4 has been recently suggested as a possible cause of CD830  T-cell apoptosis and AIDS-related dementia via induction of neuronal cell apoptosis (Hesselgesser et al. Curr. Biol. 8, 595-598 (1998); Hesselgesser et al. Curr. Biol. 7, 112-121 (1997); Hesselgesser et al. xe2x80x9cChemokines and Chemokine receptors in the Brainxe2x80x9d in Chemokines in Disease published by Humana Press (1999), Edited by C. Herbert; Herbein et al. Nature 395, 189-194 (1998); Buttini et al. Nature Med. 4, 441-446 (1998); Ohagen et al. J. Virol. 73, 897-906 (1999); Biard-Piechaczyk et al. Virology 268, 329-344 (2000); Sanders et al. J. Neuroscience Res. 59, 671-679 (2000); Bajetto et al. J. Neurochem. 73, 2348-2357 (1999); Zheng et al. J. Virol. 73, 8256-8267 (1999)).
However, the binding of chemokine receptors to their natural ligands appears to serve a more evolutionary and central role than only as mediators of HIV infection. The binding of the natural ligand, pre-B-cell growth-stimulating factor/stromal cell derived factor (PBSF/SDF-1) to the CXCR4 chemokine receptor provides an important signaling mechanism: CXCR4 or SDF-1 knock-out mice exhibit cerebellar, cardiac and gastrointestinal tract abnormalities and die in utero (Zou et al., Nature, 393:591-594 (1998); Tachibana et al., Nature, 393:591-594 (1998); Nagasawa et al. Nature 382, 635-638 (1996)). CXCR4-deficient mice also display hematopoietic defects (Nagasawa et al. Nature 382, 635-638 (1996)); the migration of CXCR4 expressing leukocytes and hematopoietic progenitors to SDF-1 appears to be important for maintaining B-cell lineage and localization of CD34+ progenitor cells in bone marrow (Bleul et al. J. Exp. Med. 187, 753-762 (1998); Viardot et al. Ann. Hematol. 77, 195-197 (1998); Auiti et al. J. Exp. Med. 185, 111-120 (1997); Peled et al. Science 283, 845-848 (1999); Qing et al. Immunity 10, 463-471 (1999); Lataillade et al. Blood 95, 756-768 (1999); Ishii et al. J. Immunol. 163, 3612-3620 (1999); Maekawa et al. Internal Medicine 39, 90-100 (2000); Fedyk et al. J. Leukocyte Biol. 66, 667-673 (1999); Peled et al. Blood 95, 3289-3296 (2000)).
The signal provided by SDF-1 on binding to CXCR4 may also play an important role in tumor cell proliferation and regulation of angiogenesis associated with tumor growth (See xe2x80x9cChemokines and Cancerxe2x80x9d published by Humana Press (1999); Edited by B. J. Rollins; Arenburg et al. J. Leukocyte Biol. 62, 554-562 (1997); Moore et al. J. Invest. Med. 46, 113-120 (1998); Moore et al. Trends cardiovasc. Med. 8, 51-58 (1998); Seghal et al. J. Surg. Oncol. 69, 99-104 (1998)); the known angiogenic growth factors VEG-F and bFGF, up-regulate levels of CXCR4 in endothelial cells, and SDF-1 can induce neovascularization in vivo (Salcedo et al. Am. J. Pathol. 154, 1125-1135 (1999)); Leukemia cells that express CXCR4 migrate and adhere to lymph nodes and bone marrow stromal cells that express SDF-1 (Burger et al. Blood 94, 3658-3667 (1999); Arai et al. Eur. J. Haematol. 64, 323-332 (2000); Bradstock et al. Leukemia 14, 882-888 (2000)).
The binding of SDF-1 to CXCR4 has also been implicated in the pathogenesis of atherosclerosis (Abi-Younes et al. Circ. Res. 86, 131-138 (2000)), renal allograft rejection (Eitner et al. Transplantation 66, 1551-1557 (1998)), asthma and allergic airway inflammation (Yssel et al. Clinical and Experimental Allergy 28, 104-109 (1998); J. Immunol. 164, 5935-5943 (2000); Gonzalo et al. J. Immunol. 165, 499-508 (2000)), Alzheimers disease (xia et al. J. Neurovirology 5, 32-41 (1999)) and Arthritis (Nanki et al. J. Immunol. 164, 5010-5014 (2000)).
In attempting to better understand the relationship between chemokines and their receptors, recent experiments to block the fusion, entry and replication of HIV via the CXCR4 chemokine receptor were carried out through the use of monoclonal antibodies or small molecules that appear to suggest a useful therapeutic strategy (Schols et al., J. Exp. Med. 186:1383-1388 (1997); Schols et al., Antiviral Research 35:147-156 (1997); Bridger et al. J. Med. Chem. 42, 3971-3981 (1999); Bridger et al. xe2x80x9cBicyclam Derivatives as HIV Inhibitorsxe2x80x9d in Advances in Antiviral Drug Design Volume 3, p161-229; Published by JAI press (1999); Edited by E. De Clercq). Small molecules, such as bicyclams, appear to specifically bind to CXCR4 and not CCR5 (Donzella et al., Nature Medicine, 4:72-77 (1998)). These experiments demonstrated interference with HIV entry and membrane fusion into the target cell in vitro. More recently, bicyclams were also shown to inhibit fusion and replication of Feline Immunodeficiency Virus (FIV) that uses CXCR4 for entry (Egberink et al. J. Virol. 73, 6346-6352 (1999)).
Additional experiments have shown that the bicyclam dose-dependently inhibits binding of 125I-labeled SDF-1 to CXCR4 and the signal transduction (indicated by an increase in intracellular calcium) in response to SDF-1. Thus, the bicyclam also functioned as an antagonist to the signal transduction resulting from the binding of stromal derived factor or SDF-1xcex1, the natural chemokine to CXCR4. Bicyclams also inhibited HIV gp120 (envelope)-induced apoptosis in non-HIV infected cells (Blanco et al. Antimicrobial Agents and Chemother. 44, 51-56 (2000)).
U.S. Pat. Nos. 5,583,131; 5,698,546; 5,817,807; 5,021,409; and 6,001,826 which are herein incorporated in their entirety by reference, disclose cyclic compounds that are active against HIV-1 and HIV-2 in in vitro tests. It was subsequently discovered and further disclosed in copending application U.S. Ser. No. 09/111,895 and U.S. Serial No. 60/172,153 that these compounds exhibit anti-HIV activity by binding to the chemokine receptor CXCR4 expressed on the surface of certain cells of the immune system. This competitive binding thereby protects these target cells from infection by HIV which utilize the CXCR4 receptor for entry. In addition, these compounds antagonize the binding, signaling and chemotactic effects of the natural ligand for CXCR4, the chemokine stromal cell-derived factor 1xcex1 (SDF-1). We further disclosed that these novel compounds demonstrate protective effects against HIV infection of target cells by binding in vitro to the CCR5 receptor.
Additionally we have disclosed in U.S. Ser. No. 09/495,298 that these cyclic polyamine antiviral agents described in the above-mentioned patents have the effect of enhancing production of white blood cells as well as exhibiting antiviral properties. Thus, these agents are useful for controlling the side-effects of chemotherapy, enhancing the success of bone marrow transplantation, enhancing wound healing and burn treatment, as well as combating bacterial infections in leukemia.
More recently, we disclosed in U.S. Ser. No. 09/535,314, a series of heterocyclic compounds that exhibit anti-HIV activity by binding to the chemokine receptors CXCR4 and CCR5 expressed on the surface of certain cells of the immune system. This competitive binding thereby protects these target cells from infection by HIV which utilize the CXCR4 or CCR5 receptors for entry. In addition, these compounds antagonize the binding, signaling and chemotactic effects of the natural ligand for CXCR4, the chemokine stromal cell-derived factor 1xcex1 (SDF-1) and/or the natural ligand for CCR5, the chemokine RANTES.
Herein, we disclose novel compounds that exhibit protective effects against HIV infection of target cells by binding to chemokine receptor CXCR4 or CCR5 in a similar manner to the previously disclosed macrocyclic compounds. In addition, these compounds antagonize the binding, signaling and chemotactic effects of the natural ligand for CXCR4, the chemokine stromal cell-derived factor 1xcex1 (SDF-1) and/or the natural ligand for CCR5, the chemokine RANTES.
Citation of the above documents is not intended as an admission that any of the foregoing is pertinent prior art. All statements as to the date or representation as to the contents of these documents is based on the information available to the applicants and does not constitute any admission as to the correctness of the dates or contents of these documents. Further, all documents referred to throughout this application are hereby incorporated in their entirety by reference herein.
The present invention provides novel compounds that bind chemokine receptors and interfere with the binding of the natural ligand thereto. The compounds of the present invention are useful as agents demonstrating protective effects on target cells from HIV infection. Other embodiments of the present invention are compounds that act as antagonists or agonists of chemokine receptors, as well as other biological activities related to the ability of these compounds to inhibit the binding of chemokines to their receptors.
The compounds of the invention are of Formula (1), including the pharmaceutically acceptable salts and pro-drug forms thereof. The compounds of Formula (1) are of the formula: 
wherein:
Ring A optionally comprises a heteroatom selected from N, O and S;
the dotted lines represent optional unsaturation;
R1, R2 and R3 are non-interfering substituents;
k is 0-4;
l is 0, 1, or 2;
X is unsubstituted or substituted C or N; or is O or S;
Ar is the residue of an aromatic or heteroarmatic moiety;
each n is independently 0-2;
each R is independently H or alkyl (1-6C);
j is 0-3; and
each Y is independently an optional substituent, as defined herein other than CR2NR(CR2)nB where B is aromatic or heteroaromatic or other heterocycle.
Preferably, each Y is independently halo, OH, SH, SO, SO2, or an organic moiety of 1-20C atoms that does not contain N wherein two such Y may be connected to form a fused ring wth Ar, or is selected from the group consisting of
xe2x80x94(CR2)mCN,
xe2x80x94(CR2)mNR52,
xe2x80x94(CR2)mNR(CR2)mNRR4,
xe2x80x94(CR2)mNR(CR2)mNR(CR2)mNR52,
xe2x80x94(CR2)mCO(CR2)mNR52,
xe2x80x94(CR2)mCO(CR2)mNR(CR2)mNRR4,
xe2x80x94(CR2)mCO(CR2)mNR(CR2)mNR(CR2)mNR52,
xe2x80x94(CR2)mNRCO(CR2)mNRR4,
xe2x80x94(CR2)mNRCO(CR2)mNR(CR2)mNR52,
xe2x80x94(CR2)mNRCO(CR2)mNR(CR2)mNR(CR2)mNR(CR2)mNR52,
xe2x80x94CHxe2x95x90Nxe2x80x94Z,
xe2x80x94(CR2)mZ,
xe2x80x94NR (CR2)mZ,
xe2x80x94(CR2)mNROH,
(CR2)mCONROH, and
(CR2)mCRxe2x95x90NOH,
and those wherein Y comprises guanidino or NHNHR, or amidino;
wherein Z is an optionally substituted aromatic or heteroaromatic moiety containing 5-12 ring members; and
wherein R is as defined above, each m is independently 0-4, and R4 and each R5 is independently H, alkyl (1-6C), alkenyl (1-6C), alkynyl (1-6C), or acyl (1-6C), each optionally substituted by one or more nonaromatic, nonheterocyclic substituent(s), and wherein two R5 may be connected to form a cyclic amine, optionally containing one or more additional heteroatoms selected from N, O, and S.
The compounds of the invention specifically exclude embodiments wherein Y is CR2NR(CR2)nB where B is aromatic or heteroaromatic or other heterocycle.
The optional substituents are defined infra.
The invention includes pharmaceutical compositions comprising a therapeutically effective amount of the compound of Formula (1); methods of treating a disease of the human body or the bodies of other mammals comprising the administration of such pharmaceutical compositions, and a method for blocking or interfering with the binding of a chemokine receptor with its natural ligand, comprising the contacting of said chemokine receptor with an effective amount of the compound of Formula (1).
This invention is also directed to use of a compound of Formula (1) in the manufacture of a medicament for the treatment of a disease in which blocking or interfering with binding of a chemokine receptor with its natural ligand is advantageous, which method may comprise formulating a composition comprising a therapeutically effective amount of the compound of Formula (1). The invention also provides a method of protecting target cells possessing chemokine receptors, the binding to which by a pathogenic agent results in disease or pathology, comprising administering to a mammalian subject a pharmaceutical composition comprising a therapeutically effective amount of the compound of Formula (1).
The compounds of the invention may be tin the form of xe2x80x9cpro-drugsxe2x80x9d, that is, protected forms of the compounds, which release the compound after administration to a patient. For example, the compound may carry a protective groups which is split off by hydrolysis in body fluids e.g. in the bloodstream, thus releasing active compound or is oxidized or reduced in body fluids to release the compound. A discussion of pro-drugs may be found in xe2x80x9cSmith and Williams"" Introduction to the Principles of Drug Designxe2x80x9d, H. J. Smith, Wright, Second Edition, London 1988.
Acid addition salts, which are pharmaceutically acceptable, such as salt with inorganic base, a salt with organic-base, a salt with inorganic acid, a salt with organic acid, a salt with basic or acidic amino acid, etc. are also encompassed in the present invention. Examples of a salt with an inorganic base include a salt with alkali metal (e.g. sodium, potassium, etc.), alkaline earth metal (e.g. calcium, magnesium, etc.), aluminum, ammonium, etc. Examples of the salt with an organic base include a salt with trimethylamine, triethylamine, pyridine, picoline, ethanolamine, diethanolamine, triethanolamine, dicyclohexylamine, N,Nxe2x80x2-dibenzylethylenediamine etc. Examples of the salt with an inorganic acid include a salt with hydrochloric acid, hydrobromic acid, nitric acid, sulfuric acid, phosphoric acid, etc. Examples of the salt with an organic acid include a salt with formic acid, oxalic acid, acetic acid, tartaric acid, methanesulfonic acid, benzenesulfonic acid, malic acid, methanesulfonic acid, benzenesulfonic acid, p-toluenesulfonic acid, etc. Examples of salts with basic amino acids include a salt with arginine, lysine, ornithine, etc. Examples of salts with the acidic amino acid include a salt with aspartic acid, glutamic acid, etc. Non-toxic in the present context has to be considered with reference to the prognosis for the infected patient without treatment.
The present invention is directed to compounds of Formula (1) which can act as agents that modulate chemokine receptor activity. Such chemokine receptors include but are not limited to CCR1, CCR2, CCR3, CCR4, CCR5, CCR6, CCR7, CCR8 and CXCR1, CXCR2, CXCR3, CXCR4 and CXCR5, preferably CXR4 and/or CCR5.
The compounds affect the binding of a natural ligand or chemokine to a receptor, such as CXCR4 and/or CCR5 of a target cell.
Thus the compounds affect chemokine receptors, such as CCR1, CCR2, CCR3, CCR4, CCR5, CCR6, CCR7, CCR8 and CXCR1, CXCR2, CXCR3, CXCR4 and CXCR5 where such chemokine receptors have been correlated as being important mediators of many human inflammatory as well as immunoregulatory diseases and cancer, and modulate the activity of such chemokine receptors so as to be useful for the treatment or prevention of such diseases.
In particular, the compounds of Formula 1 have protective effects on target cells from HIV infection in a manner as to bind specifically to the chemokine receptor.
The term xe2x80x9cmodulatorsxe2x80x9d as used herein is intended to encompass antagonist, agonist, partial antagonist, and or partial agonist, inhibitors, and activators. In the preferred embodiment of the present invention, compounds of Formula 1 demonstrate protective effects against HIV infection by inhibiting the binding of HIV to a chemokine receptor such as CXCR4 and/or CCR5 of a target cell. The invention includes a method which comprises contacting the target cell with an amount of the compound which is effective at inhibiting binding to the chemokine receptor.
The term xe2x80x9ctherapeutically effective amountxe2x80x9d means the amount of the subject compound that will elicit a biological or medical response in a cell, tissue, organ, system, animal or human that is being sought by the researcher, veterinarian, medical doctor or other clinician.
The term xe2x80x9cadministrationxe2x80x9d and or xe2x80x9cadministeringxe2x80x9d of the subject compound should be understood to mean as providing a compound of the invention including a pro-drug of a compound of the invention to the individual in need of treatment.
Compounds of the invention that inhibit chemokine receptors may be used for the treatment both prophylactic and therapeutic of diseases associated with hematopoiesis, including but not limited to, controlling the side-effects of chemotherapy, enhancing the success of bone marrow transplantation, enhancing wound healing and burn treatment, as well as combating bacterial infections in leukemia.
Compounds of the invention that inhibit chemokine receptor activity and function may be used for the treatment of diseases that are associated with inflammation, including but are not limited to, inflammatory or allergic diseases such as asthma, allergic rhinitis, hypersensitivity lung diseases, hypersensitivity pneumonitis, eosinophilic pneumonias, delayed-type hypersensitivity, interstitial lung disease (ILD) (e.g., idiopathic pulmonary fibrosis, or ILD associated with rheumatoid arthritis, systemic lupus erythematosus, ankylosing spondylitis, systemic sclerosis, Sjogren""s syndrome, polymyositis or dermatomyositis); systemic anaphylaxis or hypersensitivity responses, drug allergies, insect sting allergies; autoimmune diseases, such as rheumatoid arthritis, psoriatic arthritis, systemic lupus erythematosus, myastenia gravis, juvenile onset diabetes; glomerulonephritis, autoimmune throiditis, graft rejection, including allograft rejection or graft-versus-host disease; inflammatory bowel diseases, such as Crohn""s disease and ulcerative colitis; spondyloarthropathies; scleroderma; psoriasis (including T-cell mediated psoriasis) and inflammatory dermatoses such as dermatitis, eczema, atopic dermatitis, allergic contact dermatitis, urticaria, vasculitis (e.g., necrotizing, cutaneous, and hypersensitivity vasculitis); eosinphilic myotis, eosiniphilic fascitis; and cancers.
Compounds of the invention that activate or promote chemokine receptor function may be used for the treatment of diseases that are associated with immunosuppression such as individuals undergoing chemotherapy, radiation therapy, enhanced wound healing and burn treatment, therapy for autoimmune disease or other drug therapy (e.g., corticosteroid therapy) or combination of conventional drugs used in the treatment of autoimrmune diseases and graft/transplantation rejection, which causes immunosuppression; immunosuppression due to congenital deficiency in receptor function or other causes; and infectious diseases, such as parasitic diseases, including but not limited to helminth infections, such as nematodes (round worms); Trichuriasis, Enterobiasis, Ascariasis, Hookworm, Strongyloidiasis, Trichinosis, filariasis; trematodes; visceral worms, visceral larva migtrans (e.g., Toxocara), eosinophilic gastroenteritis (e.g., Anisaki spp., Phocanema ssp.), cutaneous larva migrans (Ancylostona braziliense, Ancylostoma caninum); the malaria-causing protozoan Plasmodium vivax, Human cytomegalovirus, Herpesvirus saimiri, and Kaposi""s sarcoma herpesvirus, also known as human herpesvirus 8, and poxvirus Moluscum contagiosum. 
One or more compounds of Formula 1 may be used in combination with any other pharmaceutical composition where such combined therapy modulates chemokine receptor activity and thereby prevent and treat diseases associated with hematopoiesis, inflammation, autoimmune, inflammatory dermatoses, cancers, inflammatory bowel diseases, and immunoregulatory disorders.
It is also contemplated that the present invention may be used in combinations with one or more agents useful in the prevention or treatment of HIV. Examples of such agents include:
(1) nucleotide reverse transcriptase inhibitor such as zidovudine, didanosine, lamivudine, zalcitabine, abacavir, stavudine, adefovir, adefovir dipivoxil, fozivudine todoxil, etc.;
(2) non-nucleotide reverse transcriptase inhibitor (including an agent having anti-oxidation activity such as immunocal, oltipraz, etc.) such as nevirapine, delavirdine, efavirenz, loviride, immunocal, oltipraz, etc.; and
(3) protease inhibitors such as saquinavir, ritonavir, indinavir, nelfinavir, amprenavir, palinavir, lasinavir, etc.
The scope of combinations of compounds of Formula (1) with HIV agents is not limited to (1), (2), and or (3), but includes in principle, any combination with any pharmaceutical composition useful for the treatment of HIV. Further, in such combinations the compounds of the present invention and other HIV agents may be administered separately or in conjunction. In addition, the administration of one element may be prior to, concurrent to, or subsequent to the administration of other agent(s).
The compounds of Formula (1) may be administered by oral, parenteral (e.g., intramuscular, intraperitoneal, intravenous, intracistemal injection or infusion, subcutaneous injection, or implant), by inhalation spray, nasal, vaginal, rectal, sublingual, or topical routes of administration and may be formulated, alone or together, in suitable dosage unit formulations containing conventional non-toxic pharmaceutically acceptable carriers, adjuvants and vehicles appropriate for each route of administration.
The compounds of Formula 1 are all active and used to treat animals, including but not limited to, mice, rats, horses, cattle, sheep, dogs, cats, and monkeys. The compounds of the invention are also effective for use in humans.
The compounds of Formula 1 may form hydrates or solvates. Those compounds of Formula 1 which can exist as regioisomers, configurational isomers, conformers, or diasteroisomeric forms may occur as mixtures of such forms. Mixtures may be treated so as to isolate individual isomers using known separation and purification methods, if desired. For example when the compound of Formula (1) is a racemate, it can be separated into the (S)-compound and (R)-compound by optical resolution. Individual optical isomers and a mixtures thereof are included in the scope of the present invention.
This invention also relates to a pharmaceutical composition comprising a pharmaceutically acceptable carrier or diluent and an effective amount of compound of Formula 1. A compound of Formula 1 may be administered alone or as an admixture with a pharmaceutically acceptable carrier (e.g. solid formulations such as tablets, capsules, granules, powders, etc.; liquid formulations such as syrups, injections, etc.) may be orally or non-orally administered. Examples of non-oral formulations include injections, drops, suppositories, pessaryies.
In the treatment or prevention of conditions which require chemokine receptor modulation an appropriate dosage level will generally be about 0.01 to 500 mg per kg patient body weight per day which can be administered in singe or multiple doses. Preferably, the dosage level will be about 0.1 to about 250 mg/kg per day. It will be understood that the specific dose level and frequency of dosage for any particular patient may be varied and will depend upon a variety of factors including the activity of the specific compound used, the metabolic stability and length of action of that compound, the age, body weight, general health, sex, diet, mode and time of administration, rate of excretion, drug combination, the severity of the particular condition, and the patient undergoing therapy.
The present invention further provides novel compounds that bind chemokine receptors and interfere with the binding of the natural ligand thereto. The compounds of the present invention are useful as agents demonstrating protective effects on target cells from HIV infection. The compounds of the present invention are also useful as antagonists or agonists of chemokine receptors, as well as other biological activities related to the ability of these compounds to inhibit the binding of chemokines to their receptors.
In the compounds of Formula 1, R may be straight or branched chain alkyl or may be cyclic, and may optionally be substituted by 1-2 substituents selected from halo, hydroxy and alkoxy. Preferably each R is H or lower straightchain alkyl (1-4C), preferably methyl.
Ar is the residue of an aromatic or heteroaromatic moiety which contains a single or fused ring system and containing 5-6 ring members in the monocyclic system and 9-12 members in the fused ring system. The residue may be optionally substituted. Examples of optionally substituted aromatic and heteroaromatic groups include benzene, naphthalene, dihydronaphthalene, tetrahydronaphthalene, pyridine, quinoline, isoquinoline, imidazole, benzimidazole, azabenzimidazole, benzotriazole, furan, benzofuran, thiazole, benzothiazole, oxazole, benzoxazole, pyrrole, indole, imidazole, tetrahydroquinoline, tetrahydroisoquinoline, pyrazole, thiophene, isoxazole, isothiazole, triazole, tetrazole, oxadiazole, thiadiazole, imidazoline, and benzopyran. Oxides of the nitrogen and sulfur containing heteroaromatic rings are also included in the present invention. Particularly preferred forms of Ar are phenylene, pyridylene or pyridinylene.
When compounds of Formula (1) contain elements that are xe2x80x9coptionally substitutedxe2x80x9d these substituents are preferably halogen, nitro, cyano, carboxylic acid, optionally substituted alkyl, alkenyl or cycloalkyl groups, an optionally substituted hydroxyl group, an optionally substituted thiol group, an optionally substituted amino, an optionally substitute acyl group, an optionally substituted carboxylate, carbamate, carboxamide or sulfonamide group, or an optionally substituted aromatic or heterocyclic group.
Examples of halogen include fluorine, chlorine, bromine, iodine, etc., with fluorine and chlorine preferred.
Examples of optionally substituted alkyl include C1-10 alkyl, including methyl, ethyl propyl etc.; examples of optionally substituted alkenyl groups include C2-10 alkenyl such as allyl, crotyl, 2-pentenyl, 3-hexenyl, etc.; and examples of optionally substituted cycloalkyl groups include C3-10 cycloalkyl such as cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, etc. In these cases, C1-6 alkyl, alkenyl and cycloalkyl are preferred. The optional substituent may also be an optionally substituted aralkyl (e.g. phenyl C1-4 alkyl) or heteroalkyl for example, phenylmethyl (benzyl), phenylethyl, pyridinylmethy, pyridinylethyl, etc. The heterocyclic group may be a 5 or 6 membered ring containing 1-4 heteroatoms.
Examples of optionally substituted hydroxyl and thiol groups include those wherein the substituent is an optionally substituted alkyl (e.g. C1-10 alkyl) such as methyl, ethyl, propyl, isopropyl, butyl, isobutyl, sec-butyl, tert-butyl, pentyl, etc., preferably (C1-6) alkyl; an optionally substituted cycloalkyl (e.g. C3-7 cycloalkyl, etc., such as cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, etc.); an optionally substituted aralkyl (e.g. phenyl-C1-4 alkyl, e.g. benzyl, phenethyl, etc.). Where there are two adjacent hydroxyl or thiol substituents, the heteroatoms may be connected via an alkylene group such as O(CH2)nO and S(CH2)nS (where n=1-5). Examples include methylenedioxy, ethylenedioxy, etc. Oxides of thio-ether groups such as sulfoxides and sulfones are also encompassed.
Further examples of the optionally substituted hydroxyl group include an optionally substituted C2-4 alkanoyl (e.g. acetyl, propionyl, butyryl, isobutyryl, etc.), C1-4 alkylsufonyl (e.g. methanesulfonyl, ethanesulfonyl, etc.) and an optionally substituted aromatic and heterocyclic carbonyl group including benzoyl, pyridinecarbonyl, etc.
The substituents on optionally substituted amino group may bind to each other to form a cyclic amino group (e.g. 5- to 6-membered cyclic amino, etc., such as tetrahydropyrrole, piperazine, piperidine, pyrrolidine, morpholine, thiomorpholine, pyrrole, imidazole, etc.). Said cyclic amino group may have a substituent, and examples of the substituents include halogen (e.g. fluorine, chlorine, bromine, iodine, etc.), nitro, cyano, hydroxy group, thiol group, amino group, carboxyl group, an optionally halogenated C1-4 alkyl (e.g. trifluoromethyl, methyl, ethyl, etc.), an optionally halogenated C1-4 alkoxy (e.g. methoxy, ethoxy, trifluoromethoxy, trifluoroethoxy, etc.), C2-4 alkanoyl (e.g. acetyl, propionyl, etc.), C1-4 alkylsulfonyl (e.g. methanesulfonyl, ethanesulfonyl, etc.) the number of preferred substituents are 1 to 3.
The amino group may also be substituted once or twice (to form a secondary or tertiary amine) with a group such as an optionally substituted alkyl group including C1-10 alkyl (e.g. methyl, ethyl propyl etc.); an optionally substituted alkenyl group such as allyl, crotyl, 2-pentenyl, 3-hexenyl, etc., or an optionally substituted cycloalkyl group such as cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, etc. In these cases, C1-6 alkyl, alkenyl and cycloalkyl are preferred. The amine group may also be optionally substituted with an aromatic or heterocyclic group, aralkyl (e.g. phenyl C1-4 alkyl) or heteroalkyl for example, phenyl, pyridine, phenylmethyl (benzyl), phenethyl, pyridinylmethyl, pyridinylethyl etc. The heterocyclic group may be a 5 or 6 membered ring containing 1-4 heteroatoms. The optional substituents of the xe2x80x9coptionally substituted amino groups are the same as defined above for the xe2x80x9coptionally substituted cyclic amino group.xe2x80x9d
The amino group may be substituted with an optionally substituted C2-4 alkanoyl e.g. acetyl, propionyl, butyryl, isobutyryl etc., or a C1-4 alkylsulfonyl (e.g. methanesulfonyl, ethanesulfonyl, etc.) or a carbonyl or sulfonyl substituted aromatic or heterocyclic ring, e.g. benzenesulfonyl, benzoyl, pyridinesulfonyl, pyridinecarbonyl etc. The heterocycles are as defined above.
Examples of the optionally substituted acyl groups include a carbonyl group or a sulfinyl or sulfonyl group binding to hydrogen; or to an optionally substituted alkyl (e.g. C1-10 alkyl such as methyl, ethyl, propyl, isopropyl, butyl, isobutyl, sec-butyl, tert-butyl, pentyl, isopentyl, neopentyl, hexyl, heptyl, octyl, nonyl, decyl, etc., preferably lower (C1-6) alkyl, etc.; an optionally substituted cycloalkyl (e.g. C3-7 cycloalkyl, etc., such as cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, etc.); an optionally substituted alkenyl (e.g. C2-10 alkenyl such as allyl, crotyl, 2-pentenyl, etc., preferably lower (C2-6) alkenyl, etc.); an optionally substituted cycloalkenyl (e.g. C3-7 cycloalkenyl, etc., such as 2-cyclopentenyl, 2-cyclohexenyl, 2-cyclopentenylmethyl, 2-cyclohexenylmethyl, etc.) an optionally substituted 5- to 6-membered monocyclic aromatic group (e.g. phenyl, pyridyl, etc.).
Examples of the optionally substituted carboxylate group (ester groups) include an optionally substituted alkyl (e.g. C1-10 alkyl such as methyl, ethyl, propyl, isopropyl, butyl, isobutyl, sec-butyl, tert-butyl, pentyl, isopentyl, neopentyl, hexyl, heptyl, octyl, nonyl, decyl, etc., preferably lower (C1-6) alkyl, etc.); an optionally substituted cycloalkyl (e.g. C3-7 cycloalkyl, etc. such as cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, etc.); an optionally substituted alkenyl (e.g. C2-10 alkenyl such as allyl, crotyl, 2-pentenyl, 3-hexenyl, etc., preferably lower (C2-6) alkenyl, etc.); an optionally substituted cycloalkenyl (e.g. C3-7 cycloalkenyl, etc., such as 2-cyclohexenylmethyl, etc.); an optionally substituted aryl (e.g. phenyl, naphthyl, etc.) and C1-4 aryl for example, benzyl, phenethyl etc. Groups such as methoxymethyl, methoxyethyl, etc., are also encompassed.
Examples of the optionally substituted carboxamide and sulfonamide groups are identical in terms of the amine definition as the xe2x80x9coptionally substituted amino groupxe2x80x9d defined above.
Examples of the optionally substituted aromatic or heterocyclic groups are phenyl, naphthyl, or a 5- or 6-membered heterocyclic ring containing 1-4 heteroatoms. The optional substituents are essentially identical to those listed above.
The noninterferring substituents R1, R2 and R3 are similar to those set forth as xe2x80x9coptional substituentsxe2x80x9d. Preferably, R1 is selected from the optional substituents set forth above, preferably halo, substituted or unsubstituted alkyl, substituted or unsubstituted hydroxyl, substituted or unsubstituted amino, substituted or unsubstituted thiol, and substituted or unsubstituted acyl. Preferably k is 0-2, preferably 0-1, and more preferably 0.
The substituents R2 and R3 are preferably selected from the preferred embodiments of R1 listed immediately above, or, more preferably, may be joined to form a saturated or unsaturated ring system, preferably a benzo ring system.
In the above Formula 1, examples of the optionally substituted ring system containing ring A are dihydroquinoline, tetrahydroquinoline, pyranopyridine, dihydropyranopyridine, thiapyranopyridine, dihydrothiapyranopyridine, dihydronaphthyridine, tetrahydronaphthyridine. Oxides of sulfur-containing heterocycles are also encompassed in the present invention. In the above ring system containing Ring A, the optional nitrogen atom may be substituted with hydrogen, a substituted alkyl, alkenyl, cycloalkyl or aryl group, or may be the nitrogen atom of a carboxamide, carbamate or sulfonamide. Preferred for 1 is l=1, it is preferred that ring A be saturated. The most preferred combination is tetrahydroquinoline.
In the above Formula 1, X may be CH (pyrrole), O (oxazole), S (thiazole), NH or NR (imidazole) where R is a C1-6 alkyl group or acyl, sulfonyl group. In Formula 1, two adjacent R1 and/or R2 and R3 may be joined to form an optionally substituted, fused 5-7 membered ring. Examples of fused ring systems include but are not limited to indole, tetrahydroindole, benzimidazole, tetrahydrobenzimidazole, azabenzimidazole, benzoxazole, tetrahydrobenzoxazole, benzothiazole, tetrahydrobenzothiazole. The preferred ring systems resulting from R2 and R3 include those which result in benzothiazole and benzoimidazole.
In the compounds of Formula 1, it is preferred that one of the (CR2)n linkers between the ring system containing ring A and ring E is that wherein n is 0, i.e., the linkage is merely a covalent bond. Also preferred embodiments of (CR2)n in this context are ethlylene or methylene, preferrably methylene. In the most preferred embodiments, the linkage between the nitrogen shown in Formula 1 and ring A is a bond and that between the nitrogen shown and ring E is CH2. As shown, ring E may be coupled to the linker through any position, but preferably through position 2, 4 or 5, most preferably through position 2.
In the compounds of Formula 1, preferred values of j are 0-2, preferrably 1-2. The embodiments of Y may be varied widely provided Y does not contain nitrogen. Thus, Y may be halo, OH, SH, SO, SO2 and the like, or a substituent of 1-20 carbons, optionally containing as a substitution, for one or more said carbons, a heteroatom such as O or S. Preferred embodiments wherein N is not present in Y include halo, optionally substituted alkyl, optionally substitued hydroxyl, optionally substituted thiol, and optionally substituted carboxylate, and a saturated or unsaturated ring. These substituents are described above. Where N is included in Y, Y is selected from the moieties set forth hereinabove. In these substituents, xe2x80x9cZxe2x80x9d is an aromatic or heteroaromatic moiety containing 5-12 ring members. Thus, Y may include a single or fused ring. Examples of preferred forms of xe2x80x9cZxe2x80x9d are identical to those set forth with regard to the aromatic residue xe2x80x9cArxe2x80x9d set forth above, but are monovalent.
As shown, in certain embodiments, R, defined as H or alkyl (1-6C), is replaced by R4 or R5 which have a broader definitions and can include the embodiments of R as well as embodying optionally substituted alkenyl, acyl, and the like as set forth above. Preferred forms of R4 and R5 include those typified by R and optionally substituted alkenyl. Also preferred are embodiments where two R5 are connected to form a cyclic amine, including those which contain one or more additional heteroatoms such as N, O, and/or S.
Preferred forms of Y when Y contains N are those wherein R is in all cases H or methyl, preferrably H and those where two R5 are coupled. Especially preferred are those of the formula
xe2x80x94(CR2)mCN, 
xe2x80x94(CR2)mNR52, 
xe2x80x94(CR2)mNR(CR2)mNRR4, 
xe2x80x94(CR2)mCO(CR2)mNR52, 
xe2x80x94(CR2)mZ, 
and
xe2x80x94NR(CR2)mZ, 
and those wherein Y comprises guanidino or NHNHR, or amidino; especially wherein (CR2)m is CH2, CH2CH2, or CH2CH2CH2, or wherein m is 0, and those wherein R4 or R5 is H or is lower alkyl, alkenyl, or hydrogen, or wherein both R5 are identical.
Particularly preferred are xe2x80x94CH2NH2, CH2CH2NH2, CH2NMe2, xe2x80x94CH2CH2NMe2, xe2x80x94CONH2, xe2x80x94CONMe2, and the like.
Preferred Z are optionally substituted residues of benzene, oxazole, imidazole, thiazole, benzimidazole, benzthiazole, benzoxazole, indole, thiophene, tetrazine, pyrimidine, pyridine, and the like.
The novel compounds of Formula 1 of the present invention may be formulated as pharmaceutical compositions that may be administered topically; percutaneously, including intravenously; orally; and by other standard routes of pharmaceutical administration to mammalian subjects as determined according to routine clinical practice.
Having now generally described the invention, the same will be more readily understood through reference to the following examples which are provided by way of illustration, and are not intended to be limiting of the present invention, unless specified.
The intermediates 8-hydroxy-5,6,7,8-tetrahydroquinoline and 8-amino-5,6,7,8-tetrahydroquinoline were prepared according to the procedures described in Bridger et al. U.S. patent application U.S. Ser. No. 09/535,314, incorporated herein by reference. The intermediate Nxe2x80x2-(1H-benzimidazol-2-ylmethyl)-Nxe2x80x2-(5,6,7,8-tetrahydro-8-quinolinyl)-1,4-benzenedimethanamine was prepared as described by Bridger et al, U.S. Patent Applications U.S. Ser. No. 60/232,891, and U.S. Ser. No. 60/234,510, incorporated herein by reference. The intermediate 1-N-tert-butoxycarbonyl-2-chloromethylbenzimidazole was prepared as described by An, H.; Wang, T.; Mohan, V.; Griffey, R. H.; Cook, P. D. Tetrahedron 1998, 54, 3999-4012.
General Procedure for N-Alkylation of (1-tert-butoxycarbonyl-1H-Benzimidazol-2-ylmethyl)-(5,6,7,8-tetrahydro-quinolin-8-yl)-amine with Mesylates or Alkyl Chlorides
To a solution of (1-tert-butoxycarbonyl-1H-Benzimidazol-2-ylmethyl)-(5,6,7,8-tetrahydro-quinolin-8-yl)-amine (or amine) (1-1.4 equivalents), N,N,-diisopropylethylamine (or K2CO3) (1.5-2 equivalents) and KI (0.05-0.16 equivalent) in CH3CN (concentration xcx9c0.1-0.2 M) was added the mesylate or alkyl chloride (such as 1-N-tert-butoxycarbonyl-2-chloromethylbenzimidazole) (1-1.4 equivalents) and the mixture stirred at 50-70xc2x0 C. for 3-25 hours, as monitored by analytical thin layer chromatography. The reaction mixture was cooled, diluted with CH2Cl2 (10 mL/mmol amine) and poured into either saturated aqueous NaHCO3 or brine (10 mL/mmol alcohol). The phases were separated and the aqueous phase extracted with CH2Cl2 (3xc3x9710 mL/mmol amine). The combined organic phases were dried (Na2SO4 or MgSO4) and concentrated under reduced pressure. The crude material was purified by chromatography to afford the desired N-alkylated product.
General Procedure A: Direct Reductive Amination with NaBH3CN
To a stirred solution of the amine (1 equivalent) in anhydrous methanol (concentration xcx9c0.1 M), at room temperature, was added the carbonyl compound (xcx9c1-2 equivalents) in one portion. Once the carbonyl had dissolved (xcx9c5 minutes), NaBH3CN (xcx9c2-4 equiv.) was added in one portion and the resultant solution was stirred at room temperature. The solvent was removed under reduced pressure and CH2Cl2 (20 mL/mmol of amine) and brine or 1.0 M aqueous NaOH (10 mL/mmol amine) were added to the residue. The phases were separated and the aqueous phase was extracted with CH2Cl2 (3xc3x9710 mL/mmol amine). The combined organic phases were dried (Na2SO4) and concentrated under reduced pressure. The crude material was purified by chromatography.
General Procedure B: Direct Reductive Amination with NaBH(OAc)3 or NaBH4 
To a stirred solution of the amine (1 equivalent) in CH2Cl2 (concentration xcx9c0.2 M), at room temperature, was added the carbonyl compound (xcx9c1-2 equivalents), glacial acetic acid (0-2 equivalents) and NaBH(OAc)3 (xcx9c1.5-3 equivalents) and the resultant solution stirred at room temperature. The reaction mixture was poured into either saturated aqueous NaHCO3 or 1.0 M aqueous NaOH (10 mL/mmol amine). The phases separated and the aqueous phase extracted with CH2Cl2 (3xc3x9710 mL/mmol amine). The combined organic phases were dried (Na2SO4) and concentrated under reduced pressure. The crude material was purified by chromatography.
Similarly, to a stirred solution of the amine (1 equivalent) in anhydrous MeOH (concentration xcx9c0.1 M), at room temperature, was added the carbonyl compound (1 equivalent). The resultant solution was stirred at room temperature or heated to reflux for 4-24 hours. NaBH4 (1-2 equivalents) was added and the resultant mixture stirred at room temperature for xcx9c20 minutes. The reaction mixture was concentrated, dissolved in CH2Cl2, washed consecutively with saturated aqueous NaHCO3 and saturated aqueous NaCl. The aqueous layers were extracted with CH2Cl2 (2xc3x97) and the combined organic extracts were dried (MgSO4) and concentrated.
General Procedure C: Reaction of Alcohols with Methanesulfonyl Chloride
To a stirred solution of the alcohol (1 equivalent) and Et3N (1.5-2 equivalents) in CH2Cl2 (or THF) (concentration xcx9c0.1 M) at room temperature (or 0xc2x0 C.) was added methanesulfonyl chloride (xcx9c1.5 equivalents) and the reaction stirred at room temperature for 0.5-1 h. The reaction mixture was poured into either saturated aqueous NaHCO3 or saturated NH4Cl (10 mL/mmol alcohol). The phases were separated and the aqueous phase extracted with CH2Cl2 (3xc3x9710 mL/mmol amine). The combined organic phases were dried (Na2SO4) and concentrated under reduced pressure. The crude material was either purified by chromatography or used without further purification in the N-alkylation step.
General Procedure D: Salt Formation Using Saturated HBr(g) in Acetic Acid
To a solution of the free base in glacial acetic acid (2 mL) was added, a saturated solution of HBr(g) in acetic acid (2 mL). A large volume of ether (25 mL) was then added to precipitate a solid, which was allowed to settle to the bottom of the flask and the supernatant solution was decanted. The solid was washed by decantation with ether (3xc3x9725 mL) and the remaining traces of solvent were removed under vacuum. For additional purification, the solid was dissolved in methanol and re-precipitated with a large volume of ether. Washing the solid with ether by decantation, followed by drying of the solid in vacuo (0.1 Torr) gave the desired compound.
Intermediates
Preparation of 4-hydroxymethylbenzaldehyde
Terephthaldicarboxaldehyde (30.02 g, 224 mmol), methanol (200 mL), palladium on activated carbon, (10%, 3.02 g) and 2-(aminomethyl)pyridine (2.3 mL, 22 mol, 0.01 mol equiv) were combined in a hydrogenation vessel and the reaction mixture was shaken on a Parr hydrogenator for 2.5 hours at 40 psi of hydrogen. The mixture was filtered through celite, the cake washed with methanol and the solvent from the eluent removed in vacuo. Purification of the crude product by column chromatography on silica gel (EtOAc/Hexanes, 1:1) afforded the title compound (23.8 g, 78%) as a white solid. 1H NMR (CDCl3) xcex44.80 (s, 2H), 7.53 (d, 2H, J=9 Hz), 7.87 (d, 2H, J=9 Hz), 10.00 (s, 1H).
Preparation of 6,7-Dihydro-5H-quinolin-8-one 
To a stirred solution of 8-hydroxy-5,6,7,8-tetrahydroquinoline (13.96 g, 93.6 mmol) in dry CH2Cl2 (400 mL) was added activated manganese dioxide (85% purity, 82.22 g, 804 mmol). The resulting heterogeneous mixture was stirred 18 h, at which point the black slurry was filtered through a cake of celite and washed with CH2Cl2 (3xc3x9750 mL). The combined washings were concentrated to afford 11.27 g (82%) of the title compound as a pale yellow solid, which was used in subsequent reactions without further purification. 1H NMR (CDCl3) xcex42.17-2.25 (m, 2H), 2.82 (t, 2H, J=7 Hz), 3.04 (t, 2H, J=6 Hz), 7.37 (dd, 1H, J=9, 6 Hz), 7.66 (dd, 1H, J=9, 1 Hz), 8.71 (dd, 1H, J=6, 1 Hz); 13C NMR (CDCl3) xcex422.2, 28.6, 39.2, 126.6, 137.3, 140.5, 147.6, 148.6, 196.5. ES-MS m/z 148 (M+H). 
Preparation of (1-tert-butoxycarbonyl-1H-Benzimidazol-2-ylmethyl)-(5,6,7,8-tetrahydroquinolin-8-yl)-amine
Using General Procedure for N-Alkylation: To a stirred solution of 8-amino-5,6,7,8-tetrahydroquinoline (7.34 g, 49.6 mmol) in dry CH3CN (250 mL) was added 1-N-tert-butoxycarbonyl-2-chloromethylbenzimidazole (13.22 g, 49.6 mmol), N,N-diisopropylethylamine (15.5 mL, 89.2 mmol) and potassium iodide (0.41 g, 8.2 mmol) and the mixture was stirred at 60xc2x0 C. for 3.5 h. Purification by column chromatography on silica gel (CH2Cl2/MeOH, 99:1 followed by 97:3 and 96:4) gave the intermediate amine (6.38 g, 34%) as an orange, sticky oil. 1H NMR (CDCl3) xcex41.76 (s, 9H), 1.81-2.10 (m, 2H), 2.25-2.37 (m, 1H), 2.72-2.89 (m, 2H), 3.77-3.84 (m, 1H), 4.39 (d, 1H, J=15.0 Hz), 4.56 (d, 1H, J=15.0 Hz), 7.00-7.06 (m, 1H), 7.27-7.37 (m, 1H), 7.64-7.74 (m, 1H), 7.90-7.96 (d, 2H, J=8.1 Hz), 8.34 (d, 1H, J=3.0 Hz); 13C NMR (CDCl3) xcex420.13, 28.48, 29.00, 29.20, 47.15, 56.89, 86.20, 115.32, 120.28, 122.06, 124.43, 124.85, 132.77, 133.74, 137.01, 142.44, 147.10, 149.22, 154.90, 157.72; ES-MS m/z 279 (M+H-boc). 
Preparation of (1H-Benzimidazol-2-ylmethyl)-(5,6,7,8-tetrahydro-quinolin-8-yl)-amine
To a stirred solution of (2-aminomethyl)benzimidazole dihydrochloride hydrate (5.96 g, 27.1 mmol) in dry MeOH (225 mL) was added 6,7-dihydro-5H-quinolin-8-one (3.99 g, 27.1 mmol) and the mixture stirred at room temperature for 69 h. To the resultant solution was added sodium borohydride (2.06 g, 54.2 mmol) in two portions and the mixture stirred for 1.5 h. The reaction mixture was concentrated in vacuo and diluted with CH2Cl2 (150 mL). The organic layer was washed with saturated aqueous sodium bicarbonate (200 mL), the aqueous layer extracted with CH2Cl2 (2xc3x9750 mL) and the combined organic layers dried (Na2SO4), filtered, and concentrated in vacuo. Purification by column chromatography on silica gel (CH2Cl2/MeOH, 99:1 followed by 98:2 and 96:4) gave the intermediate amine (3.59 g, 50%) as a yellow foam. 1H NMR (CDCl3) xcex41.66-1.90 (m, 3H), 1.91-2.00 (m, 1H), 2.00-2.17 (m, 1H), 2.33-2.69 (br m, 1H), 3.88-3.96 (m, 1H), 4.37 (d, 1H, J=3.0 Hz), 7.18-7.26 (m, 4H), 7.48 (d, 1H, J=6.0 Hz), 7.58-7.78 (br m, 1H), 8.55-8.58 (m, 1H); 13C NMR (CDCl3) xcex419.66, 29.12, 30.24, 46.62, 57.28, 122.21, 122.83, 133.55, 138.07, 146.98, 156.17, 157.73.